2025/07/08 by Elena González Prieto, Prieto, Elena González, Carl L. Rodriguez +3 · 4 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · pdf · doi:10.48550/arxiv.2507.06316
openalex publication_date 2025/07/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The recent detection of fast-moving stars in the core of Omega Centauri (ω Cen), the most massive globular cluster (GC) in the Milky Way, has provided strong evidence for the presence of an intermediate-mass black hole (IMBH). As ω Cen, is likely the accreted nucleus of a dwarf galaxy, this IMBH also represents a unique opportunity to study BH seeding mechanisms and their potential role in the formation of supermassive BHs. We present Monte Carlo N-body models of ω Cen with detailed treatments for the loss cone dynamics involving stars, binaries, and compact objects. Starting with BH seeds of 500-5000 M\odot (consistent with runaway collisions of massive stars), our cluster models grow IMBHs with masses of ∼50,000 M\odot after 12 Gyr, while successfully reproducing the present-day surface brightness and velocity dispersion profiles of ω Cen. We find a population of fast stars similar to those observed in the core of ω Cen, with the fastest stars originating from binaries that were tidally disrupted by the IMBH. The IMBH growth is primarily driven by mergers with 30-40 M\odot BHs, suggesting a present-day IMBH-BH merger rate of ∼(4-8)×10-8~\rmyr-1 in ω Cen-like GCs. Our models also predict a similar rate of tidal disruption events (∼5×10-8~\rmyr-1) which, depending on the frequency of ω Cen-like GCs per galaxy, may represent anywhere from 0.1% to 10% of the observed TDE rate.